• Journal of Institute of Control, Robotics and Systems
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• v.13 no.2
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• pp.140-146
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• 2007

This paper demonstrates the development of a mobile robot for patrol. We fuse differential GPS, angle sensor and odometry data using the framework of extended Kalman filter to localize a mobile robot in outdoor environments. An important feature of road environment is the existence of curbs. So, we also propose an algorithm to find out the position of curbs from laser range finder data using Hough transform. The mobile robot builds the map of the curbs of roads and the map is used fur tracking and localization. The patrol robot system consists of a mobile robot and a control station. The mobile robot sends the image data from a camera to the control station. The remote control station receives and displays the image data. Also, the patrol robot system can be used in two modes, teleoperated or autonomous. In teleoperated mode, the teleoperator commands the mobile robot based on the image data. On the other hand, in autonomous mode, the mobile robot has to autonomously track the predefined waypoints. So, we have designed a path tracking controller to track the path. We have been able to confirm that the proposed algorithms show proper performances in outdoor environment through experiments in the road.

• Journal of the Ergonomics Society of Korea
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• v.28 no.2
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• pp.9-16
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• 2009

The aim of this study was to evaluate the effects of the driving performance and workload according to changing driving environment and types of steering wheel. Twelve drivers who participated in this study consisted of two groups; six Japanese as the left-lane drivers who was accustomed to driving on left-hand side of the road, and six Europeans, Americans, and Korean as the right-lane drivers who was accustomed to driving on right-hand side of the road. They were asked to operate a driving simulator while using two different types of steering wheel (for the left-hand side driving and the right-hand side driving). During the experiment, a range of data were measured including driving performance, mental workload, and eye movements which were recorded in order to identify the amount of time looking towards the in-vehicle route guidance. Results indicated that the use of the steering wheel by parallel moving led to increase high attentional demand and worse glance behavior to traffic signs for the left-lane drivers. In the case of the right-lane drivers, the effects by changing driving direction were more effective than the types of steering wheel due to their habit or traits.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.10
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• pp.23-33
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• 2012

This paper is a study on precise point positioning using global navigation satellite system. This paper studies inherent barriers of global navigation satellite system such as increase in shadowed areas and positioning errors when signals cannot be received due to various environmental factors. It analyzes performance of various receivers, changes in number of satellite and DOP(Dilution of Precision) following changes in environment such as center of a road, side of a road, residential area, high building, and alleys. It also studies changes in positioning error. The objective of this study lies on understanding the range of positioning error following changes in environment and the cause of error, and enhancing the reliability and safety of the global navigation satellite system.

• Journal of Korean Society of Rural Planning
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• v.21 no.1
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• pp.89-102
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• 2015

With the basic research logic stating that the systematic improvement of rural housing plot's boundary barriers should call for the integrated consideration of their on-and-around installing settings, this study tries to analyse characteristics of installing environment of boundary barriers for improvement works of them. Through literature review and then screening process, 3 influencing and appraisal factors were determined: main house-boundary barrier shortest distance as on-site factor, building coverage as inside one, and attached road width as outside one. 21 study villages were subgrouped into structurally improved(9) and not(12). Site investigation and analysis results showed that the relationship between factors has varied very much, i.e. in some cases it is positive or complementary, but in other cases, negative or crossed. Therefore this study would propose that differentiated and flexible strategies with integrated consideration of on-and-around site installing settings be applied in their improvement projects rather than village-wide unified or straight forwarded ones.

• International Journal of Highway Engineering
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• v.10 no.4
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• pp.91-101
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• 2008

A multi layered elastic analysis program, IDYSPAP, was developed. The objective of this study was to develop the IDYSPAP program on Graphic User Interface environment for field engineers using Visual Basic, which was considered span of multi-wheels and maximum 4 axles using superposition of linear elastic theorem. It is suggested that this study considers algorithm with dynamic properties of asphalt layer on various temperature and non-linear properties of subbase and subgrade on stress non-linearity for asphalt pavement structure. This Program was modified to divide asphalt layer automatically according to layer division concept. The developed program was verified with initial measuring data in test road sections of KEC (Korea Expressway Co.) using laboratory test results.

• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.107-114
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• 2009

Human walking is essential and important mean of transportation. Pedestrian safety is recently important because accidents often happen while walking. This research is showing that Walking-environmental factors have effect on safety while walking. At first, exact 15 factors and conduct survey in the preceding research. After that, exact 4 important factors through factor analysis. At result of Multiple regression analysis, null hypothesis has proved to be true by satisfying therms which is F-value 9.211 and P-value 0.000. and come to the conclusion that walking-environmental factors influence pedestrian safety. 4 important factors can be listed by below. Pedestrian-road characteristic, landscape characteristic, commercial characteristic, walking characteristics by following influence. Especially, landscape characteristic and pedestrian-road characteristic can be vital factors.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.1
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• pp.1-8
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• 2013

Recently, the automotive technology has developed with electronics and information technology as convergence technology while vehicles had been regarded as machines. Moreover, vehicles are becoming more intelligent and safer devices, assembly of advanced technologies by customers' demand. Even though all of installations of vehicle have attracted as diverting devices, it cause drivers' mistakes like delay of response on traffic condition. Here, we proposed the Field Operational Test (FOT) environment which could be used as driving and road conditions collector(Vehicle motion, Traffic condition, Driver input, Driver state, etc.) for researches about Driver Friendly Intelligent System(SCC, LDWS, etc.), Human Vehicle Interface(Driving Workload, etc.) and Economic Drive Model. Furthermore driving patten and fuel consumption patten of drivers were analyzed by measured data and direction of future research was suggested.

• The Journal of Korea Robotics Society
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• v.5 no.3
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• pp.270-277
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• 2010

Various robot platforms have been designed and developed to perform given tasks in a hazardous environment for the purpose of surveillance, reconnaissance, search and rescue, and etc. We have considered a terrain adaptive hybrid robot platform which is equipped with rapid navigation on flat floors and good performance on overcoming stairs or obstacles. Since our special consideration is posed to its flexibility for real application, we devised a design of a transformable robot structure which consists of an ordinary wheeled structure to navigate fast on flat floor and a variable tracked structure to climb stairs effectively. Especially, track arms installed in front side, rear side, and mid side are used for navigation mode transition between flatland navigation and stairs climbing. The mode transition is determined and implemented by adaptive driving mode control of mobile robot. The wheel and track hybrid mobile platform apparatus applied off-road driving mechanism for various professional service robots is verified through experiments for navigation performance in real and test-bed environment.

• Journal of Environmental Impact Assessment
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• v.18 no.5
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• pp.301-312
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• 2009

Recently, habitat fragmentation and shrinkage has occurred because of increased road construction. As a measures mitigating the adverse effect such as eco-island by road construction, Korea has been installed eco-corridors since 1995. Using the Analytic Hierarchy Process (AHP), this study analyzed the importance of assessment items and the criteria to determine which areas require eco-corridors the most. First, related literature reviews, preliminary surveys, and expert interviews were carried out to develop assessment items and criteria for constructing the hierarchy. Second, experts were surveyed in order to determine the relative importance of the assessment items by applying the AHP. As a result, it found that the restoration of the ecological network was the most important assessment item, followed by wild animal resources in the Level 3. In the Level 4, the eighteen items were ranked in the order of their relative weight and it was found that the 'Baekdudaegan Mountain Range (0.189)' was the highest ranked item. Therefore, this approach can be applied to effective selection of the priority areas in planning eco-corridors in the national scale.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1213-1237
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• 2019

Vehicular Ad-hoc Network (VANET) facilities envision future Intelligent Transporting Systems (ITSs) by providing inter-vehicle communication for metrics such as road surveillance, traffic information, and road condition. In recent years, vehicle manufacturers, researchers and academicians have devoted significant attention to vehicular communication technology because of its highly dynamic connectivity and self-organized, decentralized networking characteristics. However, due to VANET's high mobility, dynamic network topology and low communication coverage, dissemination of large data packets (e.g. multimedia content) is challenging. Clustering enhances network performance by maintaining communication link stability, sharing network resources and efficiently using bandwidth among nodes. This paper proposes a mobility-based, multi-hop clustering algorithm, (MBCA) for multimedia content broadcasting over an IEEE 802.11p-LTE-enabled hybrid VANET architecture. The OMNeT++ network simulator and a SUMO traffic generator are used to simulate a network scenario. The simulation results indicate that the proposed clustering algorithm over a hybrid VANET architecture improves the overall network stability and performance, resulting in an overall 20% increased cluster head duration, 20% increased cluster member duration, lower cluster overhead, 15% improved data packet delivery ratio and lower network delay from the referenced schemes [46], [47] and [50] during multimedia content dissemination over VANET.